Section 206 in The Indian Contract Act, 1872
Title: Notice of revocation or renunciation.
Reasonable notice must be given of such revocation or renunciation, otherwise the damage thereby resulting to the principal or the agent, as the case may be, must be made good to the one by the other.
Title: Revocation and renunciation may be expressed or implied.
Revocation and renunciation may be expressed or may be implied in the conduct of the principal or agent respectively.
A empowers B to let A's house. Afterwards A lets it himself. This is an implied revocation of B's authority.
Title: When termination of agent's authority takes effect as to agent, and as to third persons.
The termination of the authority of an agent does not, so far as regards the agent, take effect before it becomes known to him, or, so far as regards third persons, before it becomes known to them.
(a) A directs B to sell goods for him, and agrees to give B five per cent. commission on the price fetched by the goods. A afterwards, by letter, revoke B's authority. B, after the letter is sent, but before he receives it, sells the goods for 100 rupees. The sale is binding on A, and B is entitled to five rupees as his commission.
(b) A, at Madras, by letter, directs B to sell for him some cotton lying in a warehouse in Bombay, and afterwards, by letter, revokes his authority to sell, and directs B to send the cotton to Madras. B, after receiving the second letter, enters into a contract with C, who knows of the first letter, but not of the second, for the sale to him of the cotton. C pays B the money, with which B absconds. C's payment is good as against A.
(c) A directs B, his agent, to pay certain money to C. A dies, and D takes out probate to his will. B, after A's death, but before hearing of it, pays the money to C. The payment is good as against D, the executor
Title: Agent's duty on termination of agency by principal's death or insanity.
When an agency is terminated by the principal dying or becoming of unsound mind, the agent is bound to take, on behalf of the representatives of his late principal, all reasonable steps for the protection and preservation of the interests entrusted to him.
Title: Termination of sub-agent's authority.
The termination of the authority of an agent causes the termination (subject to the rules herein contained regarding the termination of an agent's authority) of the authority of all sub-agents appointed by him.